Water-based vulcanizable adhesive composition

ABSTRACT

An aqueous vulcanizable adhesive composition, which comprises a phenol resin emulsion prepared from a water-insoluble phenol resin solution in methyl ethyl ketone and an aqueous water-soluble polymeric substance solution, and a curing agent for phenol resin, uses a partially water-miscible methyl ethyl ketone in place of a completely water-miscible organic solvent, where an amount of methyl ethyl ketone is considerably reduced. PVA, preferably aceto-acetyl-modified PVA, is used as the water-soluble polymeric substance, and the aqueous vulcanizable adhesive composition is suitably used for vulcanization bonding of a metal to (hydrogenated) NBR or acrylic rubber.

TECHNICAL FIELD

The present invention relates to an aqueous vulcanizable adhesivecomposition, and more particularly to an aqueous vulcanizable adhesivecomposition, where the amount of a harmful organic solvent to humanbodies or environments is considerably reduced.

BACKGROUND ART

In the production of composites of metal or resin with rubber such asnitrile rubber, acrylic rubber, etc., a phenol resin-based, vulcanizableadhesive is used. The phenol resin-based adhesive includes two types,i.e. alcohol-soluble type and water-soluble type. Alcohol-soluble phenolresin-based adhesive is prepared by subjecting phenol and formalin toreaction in the presence of a basic catalyst, followed by vacuumdehydration, dissolution in alcohol, neutralization with an acid,thereby improving the preservability, and finally by addition of apowdery filler. Before use, a curing agent such ashexamethylenetetramine, benzenesulfonic acid, p-toluene sulfonic acid,etc. is added thereto. To conduct bonding, the adhesive is applied tosurfaces to be bonded, and the applied surfaces are laid one uponanother, and left for standing at the ordinary temperature, therebyforming a strong, insoluble and non-meltable adhesive layer.

JP-A-53-102359 discloses a process for preparing an aqueous dispersionof phenol resin by mixing (a) substantially water-insoluble phenolresin, (b) water, (c) an organic coupling solvent, and (d) polyvinylalcohol at a sufficient temperature for a sufficient time for forming anaqueous dispersion of phenol resin, where the phenol resin is added to asolution of polyvinyl alcohol in a mixture of water and coupling solventunder shearing agitation.

It is further disclosed that the coupling solvent includes ethanol,n-propanol, isopropanol, monobutyl ether, monoisobutyl ether ormonomethyl ether acetate of ethylene glycol, monobutyl ether ormonoethyl ether acetate of diethylene glycol, propylene glycolmonopropyl ether, methoxyacetone, etc., and that these coupling agentsolvents have a complete miscibility with water, and phenol resin can beformed as a 80 wt. % solution.

However, such a process for preparing an aqueous dispersion of phenolresin can form even a stable emulsion at a high concentration such as 45wt. % solid matter concentration and in a highly viscous state, asdisclosed in said JP-A-53-102359, but actual dispersed particle sizesare considerably larger, and precipitation will take place, when usedupon dilution with water, and the object of using a coupling solvent inthe process seems not to form a good emulsion with small dispersedparticle sizes and a narrow particle size distribution, but to improvethe wettability on the metal surface and to form a film free fromcraters.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide an aqueous vulcanizableadhesive composition suitable for use in vulcanization bonding betweenmetal and rubber, using methyl ethyl ketone having a partial miscibilitywith water in place of the organic solvent having a complete miscibilitywith water, where an amount of methyl ethyl ketone is considerablyreduced.

Such object of the present invention can be attained by an aqueousvulcanizable adhesive composition which comprises a phenol resinemulsion prepared from a water-insoluble phenol resin solution in methylethyl ketone and an aqueous water-soluble polymeric substance solution,and a curing agent for phenol resin, where the methyl ethyl ketonecontent is not more than 10 wt. %.

Water-insoluble phenol resin for use in the present invention includesnovolak-type phenol resins obtained by reaction of phenols having two orthree substitutable nuclear hydrogen atoms at the o-position and/or thep-position in respect to the phenolic hydroxyl group, practically suchas phenol, m-cresol, p-cresol, p-t-butylphenol, etc., or mixturesthereof, preferably, a mixture of m-cresol and p-cresol as a residue,which is obtained by removing o-cresol as an initial distillate from amixture of three cresol isomers obtained from coal tar, together withformaldehyde in the presence of an acidic catalyst such as hydrochloricacid, oxalic acid, maleic acid, etc., alone or mixtures thereof withresol type phenol resin.

Resol type phenol resin can be used in a proportion of not more thanabout 200 parts by weight, preferably 40 to 70 parts by weight on thebasis of 100 parts by weight of novolak type phenol resin, and sucheffects as shortening of curing speed and improvement of film durabilitycan be obtained. More than 200 parts by weight of resol type phenolresin is not preferable, because of lowering of liquid stability andadhesiveness. Working of resol type phenol resin as a curing agent forthe novolak type phenol resin was found by the present applicant(JP-A-10-121020), where the resol type phenol resin is a phenol resinobtained by condensation reaction of phenols having two or threesubstitutable nuclear hydrogen atoms at the o-position and/or thep-position in respect to the phenolic hydroxyl group, such as phenol,p-cresol, m-cresol, p-t-butylphenol, etc. or mixtures thereof, withformaldehyde in the presence of a basic catalyst such as sodiumhydroxide, barium hydroxide, ammonia, tertiary amine, etc.

The aforementioned JP-A-10-121020 discloses that novolak type phenolresin and resol type phenol resin as a curing agent for the former areused as an organic solvent solution prepared by dissolving both phenolresins into a ketone such as acetone, methyl ethyl ketone, etc. or analcohol such as methanol, ethanol, etc. to a solid concentration ofabout 5 to about 20 wt. %, and the resulting organic solvent solution assuch is applied to a metal as a vulcanizable adhesive composition withNBR or acrylic rubber, whereas in the present invention about 40 toabout 60 wt. % solution in methyl ethyl ketone is prepared and used notas a vulcanizable adhesive directly but for preparing a phenol resinemulsion.

A water-insoluble phenol resin solution in methyl ethyl ketone is usedas an about 40 to about 60 wt. % solution capable of minimizing theamount of methyl ethyl ketone solvent and completely dissolving thephenol resin. Preparation of methyl ethyl ketone solution can be carriedout at room temperature under stirring for about 1 to about 2 hours.

An aqueous water-soluble polymeric substance solution includes aqueousabout 5 to about 20 wt. % solutions of polyvinyl alcohol, acetoacetylgroup (—OCOCH₂COCH₃) modified polyvinyl alcohol, polyvinylpyrrolidone,various polyvinyl ethers, polyacrylic acid, polymethacrylic acid, etc.Above all, polyvinyl alcohol having a saponification degree of 60 to 99mol. %, preferably 85 to 91 mol. % is used. From the viewpoint ofimproving a warm water resistance it is preferable to useacetoacetyl-modified polyvinyl alcohol having a saponification degree (aratio of hydroxyl group to the sum total of hydroxyl group, acetylgroup, and acetoacetyl group) of 50 to 99.5 mol. %, a modificationdegree (a ratio of acetoacetyl group to the sum total of hydroxyl group,acetyl group, and acetoacetyl group) of 0.05 to 20 mol. %, and apolymerization degree of 300 to 4,000.

An aqueous polyvinyl alcohol solution or an acetoacetyl-modifiedpolyvinyl alcohol solution can be prepared by slowly adding polyvinylalcohol or acetoacetyl-modified polyvinyl alcohol to water at roomtemperature under stirring, after the completion of addition elevatingthe temperature to about 80° to about 90° C., continuing the stirring atthat temperature for about 1 to about 2 hours, and then lowering thetemperature down to room temperature.

Phenol resin emulsion can be prepared by stirring a water-insolublephenol resin solution in methyl ethyl ketone and an aqueouswater-soluble polymeric substance solution, as mentioned above, by ahomogenizer, homo-mixer, etc. capable of conducting high speed shearingstirring. More specifically, the aqueous water-soluble polymericsubstance solution is slowly added to the methyl ethyl ketone solutionunder stirring, while increasing the stirring revolution per minutes,and further increasing the stirring revolution per minute while slowlyadding water thereto, whereby a phenol resin emulsion having a solidconcentration of 5.2 to 31 wt. % can be obtained. The mixing is soconducted as to obtain a phenol resin emulsion, which comprises 5 to 25wt. %, preferably 10 to 20 wt. %, of phenol resin, 0.2 to 6 wt. %,preferably 3 to 5 wt. %, of water-soluble polymeric substance, such as(acetoacetyl-modified) polyvinyl alcohol, etc., 3 to 40 wt. %,preferably 10 to 20 wt. %, of methyl ethyl ketone, and the balance beingwater. In place of methyl ethyl ketone, methyl n-propyl ketone, methyln-butyl ketone, methyl isobutyl ketone, etc. can be also used.

When acetoacetyl-modified polyvinyl alcohol is used as a water-solublepolymer, 0.01 to 3 wt. %, preferably 0.02 to 0.5 wt. %, of anorganometallic compound can be added to the phenol resin emulsion,whereby the water resistance can be further improved. The organometalliccompound for use to this effect includes water-soluble organotitaniumcompounds and orga-nozirconium compounds such as dihydroxytitaniumbislactate, dipropoxy-titanium bis(triethanolamine), zirconyl acetate,etc.

A curing agent for the phenol resin is added to the phenol resinemulsion thus prepared. When novolak-type phenol resin is used as aphenol resin, a resol-type phenol resin can act a curing agent, asalready mentioned before. The curing agent for the phenol resingenerally includes hexamethylenetetramine, benzenesulfonic acid,p-toluenesulfonic acid, etc., and preferably hexamethylenetetramine canbe used in a proportion of about 0.1 to about 5 parts by weight,preferably about 0.4 to about 1.5 parts by weight, on the basis of 100parts by weight of phenol resin emulsion, where it is preferable to usewater together with hexamethylenetetramine, and water is used in aproportion of not more than 1,000 parts by weight, preferably about 80to about 200 parts by weight, on the basis of 100 parts by weight ofphenol resin emulsion. When acetoacetyl-modified polyvinyl alcohol isused as a water-soluble polymeric substance, water is used in aproportion of about 100 to about 200 parts by weight. Addition of thecuring agent for the phenol resin (and water) to the phenol resinemulsion can be carried out by stirring these components for a fewminutes, thereby forming an aqueous vulcanizable adhesive composition.

The aqueous vulcanizable adhesive composition thus prepared is appliedto metals such as stainless steel, mild steel, aluminum, aluminum diecasting product, copper, magnesium, etc., or to resins such as polyamide(nylon), polyester (polyethylene terephthalate, polybutyleneterephthalate), etc. by an ordinary method, such as dipping, spraying,brush coating, roll coating, etc., dried at room temperature to about100° C. for a few minutes, baked at about 150° to about 220° C. forabout 5 to about 15 minutes, and then joined together with unvulcanizednitrile rubber compound, hydrogenated nitrile rubber compound or acrylicrubber compound, followed by press vulcanization at a vulcanizationtemperature corresponding to the type of rubber. Nitrile rubber compoundusing sulfur, or sulfur-donating com-pound, organic peroxide, etc. as avulcanizing agent or a cross-linking agent can be used as the nitrilerubber compound. Hydrogenated nitrile rubber compound using organicperoxide, etc. as a cross-linking agent can be used as the hydrogenatednitrile rubber compound. Acrylic rubber compound based on acryliccopolymer rubber copolymerized with various cross-linkable groups, usingthe corresponding vulcanizing agent or cross-linking agent can be usedas the acrylic rubber compound.

BEST MODES FOR CARRYING OUT THE INVENTION

The present invention will be described below, referring to Examples.

EXAMPLE 1

500 g of novolak type phenol resin (Phenolite TD-2106, a product ofDainippon Ink & Chemicals, Inc.) was slowly added to 500 g of methylethyl ketone (solubility in water at 20° C.: 27%) under stirring, andafter the completion of addition stirring was continued for about 1 toabout 2 hours to make complete dissolution (phenol resin solution a).

Separately, 100 g of polyvinyl alcohol (GL-05, a product of the NipponSynthetic Chemical Industry Co., Ltd.; saponification degree: 86.5 to89.0) was slowly added to 900 g of water at the ordinary temperatureunder stirring, and after the completion of addition the temperature waselevated up to 85° C. over about one hour, and stirring was continuedfor one hour, while keeping the temperature at 85° C. to make completedissolution. Then, the temperature was returned to room temperature.

500 g of the aqueous 10 wt. % polyvinyl alcohol solution was slowlyadded to 300 g of the 50 wt. % novolak type phenol resin solution inmethyl ethyl ketone under stirring at a stirring speed of about 5,000rpm, using a homogenizer capable of a high speed shearing stirring,while increasing the stirring speed up to about 12,000 rpm, and furtherincreasing the stirring speed up to about 16,000 rpm while slowly adding200 g of water thereto. Then, the high speed stirring was continued atabout 16,000 rpm for about 3 minutes to prepare a phenol resin emulsion.

533 g of the thus obtained phenol resin emulsion (solid matterconcentration: 20 wt. %), 4.5 g of hexamethylenetetramine, and 462.5 gof water were mixed together, and stirred for a few minutes to preparean aqueous vulcanizable adhesive composition (organic solvent content7.95%). The aqueous vulcanizable adhesive composition was applied to azinc phosphate-treated SPCC steel sheet test piece (thickness: 16 mm),dried at 80° C. for 3 minutes to evaporate off water, and then baked at175° C. for 10 minutes. Then, unvulcanized rubber compound of thefollowing compound formulation I or II was placed thereon and subjectedto press vulcanization at 180° C. for 6 minutes to obtain a rubber-metalcomposite with a 2 mm-thick rubber layer. (Compound formulation I) Partsby weight NBR (N237, a product of JSR) 100 SRF carbon black 93 Dioctylphthalate 15 Zinc white 5 Stearic acid 3 Antioxidant (Nocrack 224, aproduct of Ouchi-Shinko 1 Kagaku K.K.) Tetramethylthiuram disulfile 1Mercaptobenzothiazole 1 Zinc dithiocarbamate 0.8 Sulfur 0.2

(Compound formulation II) Parts by weight Active chlorine-containingacrylic rubber (PA 402, a 100 product of Unimatec Co., Ltd.) HAF carbonblack 40 Powdery silica 2 Microcrystalline wax 6 Stearic acid 34,4′-bis(2,2′-dimethylbenzyl)diphenylamine 2 Sulfur 1 Sodium stearate3.5

EXAMPLE 2

350 g of novolak type phenol resin (PSF-2803, a product of Gun EiChemical Industry Co., Ltd.) and 320 g of resol type phenol resin(Resitop PL-2108, a product of Gun Ei Chemical Industry Co., Ltd.; solidmatter concentration: 47 wt. % in methyl ethyl ketone solution) wereslowly added to 330 g of methyl ethyl ketone under stirring, and afterthe completion of addition stirring was continued for about 1 to about 2hours to make complete dissolution (phenol resin solution b).

In Example 1, the same amount of the phenol resin solution b was used inplace of phenol resin solution a to conduct preparation of a phenolresin emulsion, preparation of an aqueous vulcanizable adhesivecomposition (organic solvent content: 7.95%), and making of arubber-metal composite.

EXAMPLE 3

350 g of novolak type phenol resin (Phenolite TD-2106) was slowly addedto 330 g of methyl ethyl ketone under stirring, and after the completionof addition stirring was continued for about 1 to about 2 hours to makecomplete dissolution. Then, 320 g of resol type phenol resin (ResitopPL-2108; solid matter concentration: 47 wt. % in methyl ethyl ketonesolution) was added thereto, and mixed and stirred for a few minutes(phenol resin solution c).

In Example 1, the same amount of the phenol resin solution c was used inplace of phenol resin solution a to conduct preparation of a phenolresin emulsion, preparation of an aqueous vulcanizable adhesivecomposition (organic solvent content: 7.95%), and making a rubber-metalcomposite.

EXAMPLE 4

100 g of acetoacetyl-modified polyvinyl alcohol (Gosefimer Z-320, aproduct of the Nippon Synthetic Chemical Industry Co., Ltd.;saponification degree: 93 mol. %, modification degree: 5.7 mol. %) wasslowly added to 900 g of water at the ordinary temperature understirring, and after the completion of addition the temperature waselevated up to 85° C. over about one hour, and stirring was continuedfor one hour, while keeping the temperature at 85° C. to make completedissolution, and then the temperature was returned to room temperature.

250 g of the aqueous 10 wt. % acetoacetyl-modified polyvinyl alcoholsolution was slowly added to 400 g of the phenol resin solution a usedin Example 1 under stirring at a stirring speed of about 5,000 rpm,using a homogenizer capable of high speed shearing stirring, whileincreasing the stirring speed up to about 12,000 rpm, and furtherincreasing the stirring speed up to about 16,000 rpm while slowly adding350 g of water thereto. Then, high speed stirring was continued at about16,000 rpm for about 3 minutes to prepare a phenol resin emulsion.

400 g of the thus obtained phenol resin emulsion (solid matterconcentration: 22.5 wt. %), 4.5 g of hexamethylenetetramine, and 595.5 gof water were mixed together, and stirred for a few minutes to preparean aqueous vulca-nizable adhesive composition (organic solvent content:8%). A rubber-metal composite was prepared, using the aqueousvulcanizable adhesive composition in the same manner as in Example 1.

EXAMPLE 5

In Example 4, the same amount of the phenol resin solution c used inExample 3 was used in place of the phenol resin solution a.

EXAMPLE 6

In Example 4, the same amount of the phenol resin solution c was used inplace of phenol resin solution a, and after the preparation of thephenol resin emulsion, 2 g of dihydroxytitanium bislactate was addedthereto, followed by stirring at about 3,000 rpm for about 3 minutes.The resulting emulsion was used.

REFERENCE EXAMPLE

Example 1, a solvent-based vulcanizable adhesive composition (organicsolvent content: 90.6%) comprising 90 g of novolak type phenol resin(Phenolite TD-2106), 4.5 g of hexamethylenetetramine, and 905.5 g ofmethanol was used as a vulcanizable adhesive composition.

The rubber-metal composites obtained in the foregoing Examples andReference Example were subjected to determination of bonding strength(according to JIS K-6256 90° peeling test) and percent retained rubberarea (according to the same procedure as above) at the initial and warmwater (80° C.) dipping for 70 hours and 140 hours. The results are shownin the following Table 1 (compound formulation I) and Table 2 (compoundformulation II). TABLE 1 Bonding strength (N/mm) Percent retained rubberarea (%) Warm Warm Warm Warm water water water water dipping dippingdipping dipping Example Initial 70 hrs 140 hrs Initial 70 hrs 140 hrsEx. 1 19.2 5.6 4.8 100 0 0 Ex. 2 19.4 8.0 5.0 100 20 0 Ex. 3 19.1 7.95.0 100 10 0 Ex. 4 19.3 18.0 16.3 100 90 50 Ex. 5 19.3 18.5 17.8 100 10070 Ex. 6 19.2 19.0 18.2 100 100 95 Ref. Ex. 19.3 19.2 19.2 100 100 100

TABLE 2 Bonding strength (N/mm) Percent retained rubber area (%) WarmWarm Warm Warm water water water water dipping dipping dipping dippingExample Initial 70 hrs 140 hrs Initial 70 hrs 140 hrs Ex. 1 9.0 2.5 1.9100 0 0 Ex. 2 9.1 3.0 2.0 100 10 0 Ex. 3 8.9 3.4 2.3 100 5 0 Ex. 4 9.17.3 6.0 100 95 80 Ex. 5 9.1 7.7 6.2 100 100 90 Ex. 6 9.2 7.7 6.8 100 100100 Ref. Ex. 9.0 7.7 6.8 100 100 100

Median diameter of the phenol resin emulsion was determined by aparticle size distribution meter (LA-910, a product of Horiba, Ltd.),and found to be 0.3 to 0.5 μm (Examples 1 and 2), or 0.3 to 0.6(Examples 3 to 6) throughout all the compound formulations. According tothe disclosure of JP-A-53-102359, polyvinyl alcohol (GL-05, a product ofthe Nippon Synthe-tic Chemical Industry Co., Ltd.) was dissolved in anaqueous 20 wt. % methanol solution, and novolak type phenol resin powder(Phenolite TD-210) was slowly added to the solution while subjecting thesolution to a high speed shearing stirring (5,000 rpm), and then thestirring speed was increased up to 16,000 rpm, followed by continuingthe stirring at that speed for 3 minutes to obtain a phenol resinemulsion (composition: 92.5 parts of phenol resin, 7.5 parts of PVA,97.6 parts of water, and 24.4 parts of methanol; solid matterconcentration: 45 wt. %). Median diameter of the thus obtained emulsionwas determined and found to be 2.5 to 7.5 μm.

Example 1 shows equivalent initial bonding strength and initial percentretained rubber area to those of Reference Example, and thus shows aninitial adhesiveness on the same level as that of the organic solventsystem, while considerably reducing the content of harmful organicsolvent to human bodies and environments. Examples 2 and 3 using thenovolak type phenol resin and the resol type phenol resin together showimproved bonding strength and percent retained rubber area against warmwater.

Example 4 also shows equivalent bonding strength and percent retainedrubber area to those of Reference Example as to the warm water-resistantadhesiveness, and thus shows a warm water-resistant adhesiveness on thesame level as that of the organic solvent system, while considerablyreducing the content of harmful organic solvent to human bodies andenvironments. Examples 5 and 6 using the novolak type phenol resin andthe resol type phenol resin together also show good bonding strength andpercent retained rubber area as to the warm water-resistantadhesiveness, and particularly owing to use of an organometalliccompound together Example 6 shows substantially equivalent bondingstrength and percent retained rubber area to those of Reference Example.

It is also evident that phenol resin emulsions of all the Examples areformed in good quality.

INDUSTRIAL UTILITY

In a phenol resin emulsion for use in the formation of the presentaqueous vulcanizable adhesive composition, the amount of methyl ethylketone, a harmful organic solvent to human bodies and environments, canbe limited to the necessary minimum one due to the use of awater-insoluble phenol resin as a highly concentrated phenol resinsolution in methyl ethyl ketone, and a good emulsion can be formed dueto the use of the solution in methyl ethyl ketone. Methyl ethyl ketoneis a partially water-miscible solvent (solubility in water at 20° C.:27%), whereas when an organic coupling solvent, etc. disclosed inJP-A-53-102359, which is completely miscible with water, are used inplace of methyl ethyl ketone, only the water-soluble organic solvent isdissolved into water at the time of mixing with an aqueous water-solublepolymeric substance solution, and the phenol resin itself is depositedto gell, that is, in the same manner as if the phenol resin powder weredirectly dispersed into an aqueous solution, and no emulsion of goodquality is obtainable. In the case of using methyl ethyl ketone, on theother hand, the phenol resin can be emulsified as a solution in methylethyl ketone, so a phenol resin emulsion of good quality with smallerdispersed particle sizes and a narrow uniform particle size distributioncan be formed.

The present aqueous vulcanizable adhesive composition comprising thephenol resin emulsion and hexamethylenetetramine can give a rubber-metalcomposite having an equivalent adhesiveness to that of an organicsolvent (methanol) type vulcanizable adhesive composition of theforegoing Reference Example, as shown in the results of the foregoingExamples, while reducing the amount of methyl ethyl ketone contained inthe present aqueous vulcanizable adhesive composition to not more than10 wt. % on the basis of the composition.

Furthermore, the present aqueous vulcanizable adhesive composition usingacetoacetyl-modified polyvinyl alcohol as a water-soluble polymer cangive a warm water-resistant adhesiveness on substantially the same levelas that of the organic solvent (methanol) type vulcanizable adhesivecomposition of the foregoing Reference Example.

1. An aqueous vulcanizable adhesive composition, which comprises aphenol resin emulsion prepared from a water-insoluble phenol resinsolution in methyl ethyl ketone and an aqueous water-soluble polymericsubstance solution, and a curing agent for phenol resin. resin, thecontent of methyl ethyl ketone being not more than 10 wt. %.
 2. Anaqueous vulcanizable adhesive composition according to claim 1, whereinthe phenol resin emulsion comprises 5 to 25 wt. % of water-insolublephenol resin, 0.2 to 6 wt. % of water-soluble polymeric substance, and 3to 40% of methyl ethyl ketone, the balance being water.
 3. (canceled) 4.An aqueous vulcanizable adhesive composition according to claim 1,wherein the water-insoluble phenol resin is a novolak type phenol resinor a mixture of a novolak type resin with a resol type phenol resin. 5.An aqueous vulcanizable adhesive composition according to claim 4,wherein not more than 200 parts by weight of the resol type phenol resinis used on the basis of 100 parts by weight of the novolak type phenolresin.
 6. An aqueous vulcanizable adhesive composition according toclaim 1, wherein the water-insoluble phenol resin is used as a solutionat a concentration of 40 to 60 wt. % in methyl ethyl ketone.
 7. Anaqueous vulcanizable adhesive composition according to claim 1, whereinthe water-soluble polymeric substance is polyvinyl alcohol.
 8. Anaqueous vulcanizable adhesive composition according to claim 1, whereinthe water-soluble polymeric substance is acetoacetyl-modified polyvinylalcohol.
 9. An aqueous vulcanizable adhesive composition according toclaim 8, wherein the phenol resin emulsion further includes anorganometallic compound.
 10. An aqueous vulcanizable adhesivecomposition according to claim 1, wherein the curing agent for phenolresin is hexamethylene-tetramine.
 11. An aqueous vulcanizable adhesivecomposition according to claim 10, wherein 0.1 to 5 parts by weight ofthe hexamethylenetetramine is used on the basis of 100 parts by weightof the phenol resin emulsion.
 12. An aqueous vulcanizable adhesivecomposition according to claim 10, wherein water is use together withhexamethylenetetramine.
 13. An aqueous vulcanizable adhesive compositionaccording to claim 12, wherein not more that 1,000 parts by weight ofthe water is used on the basis of 100 parts by weight of the phenolresin emulsion.
 14. An aqueous vulcanizable adhesive compositionaccording to claim 1, for used in vulcanization bonding of a metal orresin to rubber.
 15. An aqueous vulcanizable adhesive compositionaccording to claim 14, wherein the rubber is nitrile rubber,hydrogenated nitrile rubber or acrylic rubber.
 16. A composite of rubberand metal or resin vulcanization bonded by an aqueous vulcanizableadhesive composition according to claim
 1. 17. A phenol resin emulsionprepared from a water-insoluble phenol resin solution in methyl ethylketone and an aqueous water-soluble polymeric substance solution.